TopGear.com at F1 testing in Jerez

One thing that stood out from what you'll normally see on your Sunday sofa: many of the cars were running an Excalibur-esque antenna that sat above the airbox, rather like a sword in a stone.

Confused, we sought out Mark Smith, Technical Director of Caterham F1. He told us that teams attach a range of different instruments, designed to measure anything from airspeed to temperatures and airflow. They provide extra data, helping engineers and designers back at the factory make subtle tweaks to the car's aerodynamics and exhausts that can win, or lose, crucial tenths on track. There's such a limited time to actually get the cars on track, they need as much info as possible before fine tuning in simulators back home.